Repower of a single screw Commander 27: Options?

I am looking for my first boat, and I have run across a late 1960s Commander 27 that seems to be in good shape. It has what seems to be the original Crusader 350. If I were to buy it, I'd probably want to repower it down the line, as I would prefer to cruise in the mid 20s without draining my entire 401k to see the great blue sea (lots of ground to cover!).

Can the forum help me understand my options, particularly given the dimensions of the 27' bilge?

Replies to This Discussion

It would not have been born with a 350, probably a 327F, possibly a 327Q. The 350 should be a good choice for the size and weight, an upgrade would be the MPFI version with computer control, I don't think additional power would give any advantage, but trim tabs with individual side controls should be considered. The owners of the 27's will soon chime in, welcome aboard and keep us posted, pictures welcomed.

To dovetail what Tim said, don’t be so sure that “new” equals faster or cheaper. Like Dick said in another post, speed costs, and at some point you may not get the return you’re hoping for. Take a look at some of the brand new cruisers with diesels and I/O’s. Sure you can push a 38’ boat to near 30kts, but the fuel consumption isnt that impressive. Don’t underestimate the efficiencies of a well-tuned engine and the right cruising speed. Many on this forum get very respectable economy and performance out of 50 year old motors *cough*Tim Toth*cough*.

Also, be sure to take into consideration workload on the engines. An engine that operates at 60-70% of its total power and 2900RPM to give you a 20kt Cruise will likely give you more longevity (less stress on the motor) than one you have to push to 3500RPM and 75% to get 25kts

Hello and welcome to this Club and boating. If you are ready to make an offer on this boat, make it subject to a survey, then find a marine surveyor to go through the boat with you. This will cost a few bucks, but will be worth it. Don't be scared away by the to-do list that this produces, it's a boat. If He/She finds a major issue, then it becomes decision time. Why are you looking to repower? The Crusader 350 was a very popular choice for marine engines. Crusader produced several different versions of this engine starting in the late 60's ranging from 260 to 300 H.P. New high performance versions will produce 350 H.P. Tim is correct when he says this is not the original engine for this boat. Chances are it is much newer then the hull. A surveyor should be able to tell you the year of this one. Parts for this engine, and a mechanic who will work on it are easy to find.

If you’re looking to repower on the thought that a newer engine will use less fuel I would curb that idea. You’ll never recoup the fuel saving from the repower as even MPI fuel injected engines will burn within a few percent of the original carbureted engine. It’s not like a car where carburetors were inefficient because they never stay at the same rpm for long and are often at idle. Carburetors don’t adjust as well to changing conditions as efi does, so in the case of a car great gains could be had. On a boat you spend alot if time running the same rpm under load. In these cases a well tuned carb theoretically should be able to perform just as efficiently as efi, in reality it still won’t be perfect but will be pretty close. Now if you just want to repower because you want a newer more powerful engine a 6.2L Crusader or Mercruiser would probably work well. If you’re wanting to go faster though I would really just look at a twin engine.

I understand the sweet spot between engine performance, mileage and gas consumption...as well as longevity drawbacks of trying to push too much at the top end (and getting a survey). I grew up on Lymans so I understand inboards pushing big heavy boats. My question is more technical in nature.

What is in the boat now is a red block, carbed, Crusader 350 cid with 1k freshwater hours (which means likely 1980s)...likely 250 hp. I know the hull is rated to 400+ HP due to the twinscrew configuration (and I understand the hull will really move with that powerplant). So I am trying to understand what single screw can most closely replicate the power of the twinscrews while still staying at a reasonable fuel burn rate....without major retrofitting of the bilge, deck or transmission.

Maybe it's not possible, but I was hoping to know what my real world options are before I put an offer on the boat.

Any small block Chevy will fit, the biggest without getting into a race engine is a 383, which is a stroked and bored 350. They can be had in a 350hp 430ftlbs tourqe rating. That may be pushing the transmission beyond its limits depending on what transmission it has. The Paragon it would have come with originally would only be rated to 260hp. If they replaced the paragon with a velvet drive when they repowered they probably used a 71C. That trans might handle a 383 if your gentle with it, they have a 350hp max, but only 396ftlb tourqe. Depending how the build the motor it could exceed that. Really though I wouldn’t bother mating a new power plant up to an old transmission, just asking for trouble.

Mike, this is perfect. Thank you. I agree, if you are gonna repower, just do the whole darn thing at once, spend a little to save a lot.

Just trying to figure out the best compromise between a number of factors: newer boat/risk of major cored hull issues (80s Tiara), not wanting to spend a gazillon $$ for my dream boat (a Blue Star 30 or Back Cove 29), buying a more recent ugly but bulletproof hull (Stamas), downsizing to a smaller boat (Limestone 24) or spending a gazillion dollars in maintenance for my perfect woodie (a 68 Lyman Express cruiser).

I was thinking a repowered CCC might be a nice compromise between all of these. Who knows ;)

I have a 1969 27 single (Chris Craft 350Q, circa 1990) and Steve in western Mass has a 27 with twins. Mine will get within 4-5 mph of his. My single tops out at around 25 knots at 4,000 rpm. I like mine better LOL Half the maintenance, half the weight, lots more room below deck. With three of us and two dogs aboard, our boat is plenty fast for us.

I'm not a surveyor but I'd be happy to take a look with you at any 27 in this area (I'm 40 miles north of Boston).

Hi Jim...thank you for the info. What is your good cruising speed? And what is your consumption rate? Do you have a single tank, or the double tanks? I get a wee bit leery of these single older Crusaders, as I think weekend trips to Midcoast Maine (100 nm) will be a regular occurrence.....and I don't want to spend the entire day getting there and the entire day getting home.

I have a line on a much newer (mid 80s) Tiara with a pair of virtually brand new Crusaders that will easily cruise in the mid 20s. But her interior is much darker than the CC (and Tiaras did have some limited coring issues) and they are pretty common boats (I love more unique styles). And, it will be $15k+ more than the CC. But the motors are virtually brand new and the transmissions are new last fall (and was mechanic owned) so it's probably a better value than the CC.

The CC I have found is in the Finger Lakes, so it's well out of the way of Southern NH, but I certainly appreciate the offer.

Honestly, I would love to own the Lyman Express that has been for sale since last summer up in Maine...but I think it will be too much upkeep for little ole me.

We're comfortable at 20 knots / 23 mph. We only have one 48 gallon tank. I've been doing mods to the boat since I got it, and have never run it at cruise for a whole tankful. When we brought it down from Falmouth ME it was getting about .75 mpg - filled up at Kennebunkport and ran out of gas in Newburyport. New prop and electronic ignition have helped a lot. Next is to cut off the seems-like-lead swim platform and reinstall trim tabs. That should get it up close to 2mpg. I also want to put another, or a bigger, tank in it. No reason a 27 single in good working order shouldn't get at least 2 mpg.

That one in Queensbury NY does look nice. Maybe slightly overpriced depending on how old the Crusader is. No trailer, no hardtop though.

The 2018 Chris-Craft Commander Club National Rendezvous is in the books and it was a great time!!

The city of Mentor, Ohio and the Lawnfield Inn & Suites were wonderful hosts. A special Thanks to Rob Kneen, the local member sponsor, and Char Pike for the hours of hard work put in organizing and coordinating an amazing weekend.

The Rendezvous Photo Albums can be accessed through the links below, as well as, under Library, Photo Albums. We will continue to add links to other albums as they become available. Also below, you will find links to a couple articles written for the local newspaper.